Technologycal inovation, resource allocation and growth

Technological Innovation, Resource Allocation and Growth∗ Leonid Kogan† Dimitris Papanikolaou‡ Amit SeruĐ Noah Stoffmanả May, 2016 Abstract We propose a new measure of the economic importance of each innovation Our measure uses newly collected data on patents issued to US firms in the 1926 to 2010 period, combined with the stock market response to news about patents Our patentlevel estimates of private economic value are positively related to the scientific value of these patents, as measured by the number of citations that the patent receives in the future Our new measure is associated with substantial growth, reallocation and creative destruction, consistent with the predictions of Schumpeterian growth models Aggregating our measure suggests that technological innovation accounts for significant medium-run fluctuations in aggregate economic growth and TFP Our measure contains additional information relative to citation-weighted patent counts; the relation between our measure and firm growth is considerably stronger Importantly, the degree of creative destruction that is associated with our measure is higher than previous estimates, confirming that it is a useful proxy for the private valuation of patents JEL classifications: G14, E32, O3, O4 ∗ We thank Hal Varian for helping us in extracting information on Patents from Google Patents database We are grateful to Andrew Atkeson, Nick Bloom, Andrea Eisfeldt, Yuriy Gorodnichenko, Roel Griep, Pete Klenow, Danielle Li, Jonathan Parker, Tomasz Piskorski, and Heidi Williams for detailed comments We also thank numerous other discussants and participants at the AEAs, Boston University, Columbia Business School, Duke/UNC Asset Pricing Conference, FRB Chicago, NBER Asset Pricing, NBER Economic Fluctuations and Growth, NBER Entrepreneurship, NBER Productivity, Minnesota, Northwestern, NYU, and SITE for helpful discussions We are grateful to Tom Nicholas for sharing his patent citations data The authors thank the Fama-Miller Center at University of Chicago, the Zell Center and the Jerome Kenney Fund for financial assistance † MIT Sloan and NBER ‡ Kellogg School of Management and NBER § Booth School of Business and NBER ¶ Kelly School of Business Electronic copy available at: https://ssrn.com/abstract=2193068 Since Schumpeter, economists have argued that technological innovation is a key driver of economic growth Models of endogenous growth have rich testable predictions about both aggregate quantities and the cross-section of firms, linking improvements in the technology frontier to resource reallocation and subsequent economic growth However, the predictions of these models are difficult to test directly, mainly due to the scarcity of directly observable measures of technological innovation To assess the importance of technological innovation for economic growth, an ideal measure should capture the economic value of new inventions, and be comparable both across industries and across time This paper aims to fill this gap by constructing a new measure of the economic importance of each innovation We propose a new measure of the private, economic value of new innovations that is based on stock market reactions to patent grants We construct this measure combining a novel dataset of patent grants over the period 1926 to 2010 with stock market data.1 The advantage of using financial data is that asset prices are forward-looking and hence provide us with an estimate of the private value to the patent holder that is based on ex-ante information This private value need not coincide with the scientific value of the patent – typically assessed using forward patent citations For instance, a patent may represent only a minor scientific advance, yet be very effective in restricting competition, and thus generate large private rents These ex-ante private values are useful in studying firm allocation decisions, estimating the (private) return to R&D spending, and assessing the degree of creative destruction and reallocation that results following waves of technological progress Further, the fact that our measure of ‘quality’ is in terms of dollars implies that our estimates are comparable across time and across different industries; in contrast, since patenting propensities could vary, comparing patent counts across industries and time becomes more challenging We construct an estimate of the private value of the patent by exploiting movements in stock prices following the days that patents are issued to the firm We first document that trading activity in the stock of the firm that issued a patent increases after the patent issuance date Second, we find that returns on patent grant days are more volatile than on days without any patent grant announcement, suggesting that valuable information is released to the market However, even within a narrow window around grant days, stock prices may move for reasons that are unrelated to patent values To filter the component of firm return that is related to the value of the patent from noise, we make several distributional assumptions Several robustness checks suggest that our estimates are not overly sensitive to the particular choice of underlying distributions The resulting distribution of the estimated patent values is fat-tailed, consistent with past research describing the nature of radical innovations (Harhoff, Scherer, and Vopel, 1997) The characteristics of innovating firms and industries are similar to those discussed in Baumol (2002), Griliches (1990), Scherer (1965) Several new studies exploit the same source of patent data (Google Patents) as we in our paper For instance, see Moser and Voena (2012), Moser, Voena, and Waldinger (2012) and Lampe and Moser (2011) Ours is the first to exploit this data at a large scale and match it to firms with stock price data Electronic copy available at: https://ssrn.com/abstract=2193068 and Scherer (1983) who describe firms that have conducted radical innovation and have been responsible for technical change in the U.S To illustrate the usefulness of our measure, we use it to examine three important questions in the literature on innovation and growth Addressing these issues using existing measures has proved to be a challenge First, the relation between the private and the scientific value of innovation – as measured by patent citations – has been the subject of considerable debate.2 We examine the relation between our measure and the number of citations that the patent receives in the future We find that our patent-level estimates of economic value are strongly positively related to forward citations; this correlation is robust to a number of patent- and firm-level controls Placebo experiments confirm that this relation is unlikely to be spurious In terms of economic magnitudes, our results are comparable to Hall et al (2005); an additional patent citation is associated with an increase of 0.1% to 3.2% in the economic value of a patent Second, we use our estimate of the market value of innovation to examine the predictions of models of endogenous growth (e.g Romer, 1990; Aghion and Howitt, 1992; Grossman and Helpman, 1991; Klette and Kortum, 2004) Since the value of a firm’s innovative output is hard to observe, constructing direct empirical tests of these models has proven challenging; existing approaches rely on indirect inference (see, e.g Garcia-Macia, Hsieh, and Klenow, 2015) A unifying prediction of Schumpeterian models of growth is that firms grow through successful innovation – either through acquiring new products or by improving existing varieties By contrast, innovation by competing firms has a negative effect – either directly through business stealing, or indirectly through movements in factor prices The strength of these effects depends on the economic value of the new inventions Our results using several measures of firm size – the nominal value of output, profits, capital and number of employees – suggest that both channels are important Firms that experience a onestandard deviation increase in their innovation output experience higher growth of 2.5% to 4.6% over a period of five years Conversely, firms that fail to innovate in an industry that experiences a one-standard deviation increase in its innovative output experience lower growth of 2.7% to 5.1% over the same horizon In addition to firm growth, we find similar effects on revenue-based productivity (TFPR) Firms that innovate experience productivity increases, whereas those that fall behind see productivity declines By revealing a strong relation between innovation, firm growth and the reallocation of resources across firms – For instance, Hall, Jaffe, and Trajtenberg (2005) and Nicholas (2008) document that firms owning highly cited patents have higher stock market valuations Harhoff, Narin, Scherer, and Vopel (1999) and Moser, Ohmstedt, and Rhode (2011) provide estimates of a positive relation using smaller samples that contain estimates of economic value By contrast, Abrams, Akcigit, and Popadak (2013) use a proprietary dataset that includes estimates of patent values based on licensing fees and show that the relation between private values and patent citations is non-monotonic Our approach allows us to revisit this question at a higher level of granularity than Hall et al (2005), while using a broader sample than Harhoff et al (1999), Moser et al (2011) and Abrams et al (2013) Electronic copy available at: https://ssrn.com/abstract=2193068 capital and labor flow to innovating firms and away from their competitors – these findings support the Schumpeterian view of growth and creative destruction Third, we assess the role of technological innovation in accounting for medium-run fluctuations in aggregate economic growth and TFP A notable challenge facing real business cycle models is the scarcity of evidence linking movements in TFP to clearly identifiable measures of technological change At the aggregate level, whether technological innovation is socially valuable in endogenous growth models depends on the degree to which it contributes to aggregate productivity – as opposed to simply being a force for reallocation and creative destruction Our firm-level results, when aggregated using all the firms in our sample, are strongly suggestive of a net positive effect of innovation However, these effects are confined to the sample of public firms that we study To study the relation between innovation and growth more broadly at the economy level, we construct an aggregate index of innovation based on our estimated patent values This index is motivated by a simple growth model, in which, under certain assumptions, firm monopoly profits from innovation are approximately linearly related to aggregate improvements in output and TFP Our index captures known periods of high technological progress, namely the 1920s, the 1960s and the 1990s (Field, 2003; Alexopoulos and Cohen, 2009, 2011; Alexopoulos, 2011) This innovation index is strongly related to aggregate growth in output and TFP In particular, a one-standard deviation increase in our index is associated with a 1.6% to 6.5% increase in output and a 0.6% to 3.5% increase in measured TFP over a horizon of five years, depending on the specification Our measure speaks to the literature that has spent considerable effort in estimating the value of innovative output The most popular approach consists of using citation-weighted patent counts (Hall et al., 2005) We find that our innovation measure contains considerable information about firm growth in addition to what is contained in patent citations In particular, we repeat our firm-level analysis replacing our measure with citation-weighted patent counts – both for the firm and for its competitors When doing so, we find a comparable – though somewhat weaker – relation between the firm’s own innovation output and future growth However, we find no similar negative link between the firm’s future growth and the citation-weighted patenting output of its competitors We find similar results when we include both our estimated patent values and citation-weighted patent counts in the same specification These findings are consistent with the view that, relative to the patent’s forward citations, our estimated value of a patent is a better estimate of its private economic value Our work is related to the literature in macroeconomics that aims to measure technological progress Broadly, there are three main approaches to identifying technology shocks The first two approaches measure technology shocks indirectly One approach is to measure technological change – either at the aggregate or at the firm level – through TFP (see e.g Olley and Pakes, 1996; Basu, Fernald, and Kimball, 2006) However, since these TFP measures are based on residuals, they could incorporate other forces not directly related Electronic copy available at: https://ssrn.com/abstract=2193068 to technology, such as resource misallocation (see e.g., Hsieh and Klenow, 2009) In the second approach, researchers have imposed model-based restrictions to identify technology shocks either through VARs or through estimation of structural models (see e.g., Gali, 1999; Smets and Wouters, 2003) The resulting technology series are highly dependent on specific identification assumptions Our paper falls into the third category, which constructs direct measures of technological innovation using micro data (Shea, 1999; Alexopoulos, 2011).3 We are not the first to link firm patenting activity to stock market valuations (see, e.g Pakes, 1985; Austin, 1993; Hall et al., 2005; Nicholas, 2008) In particular, Pakes (1985) examines the relation between patents and the stock market rate of return in a sample of 120 firms during the 1968–1975 period His estimates imply that, on average, an unexpected arrival of one patent is associated with an increase in the firm’s market value of $810,000 The ultimate objective of these papers is to measure the economic value of patents; in contrast, we use the stock market reaction as a means to an end—to construct appropriate weights for an innovation measure which we can be employed to study different issues in the literature on innovation and growth Our paper contributes to the literature that studies the determinants of firm growth rates Early studies show considerable dispersion in firm growth that is weakly related to size (see, e.g Simon and Bonini, 1958) Our paper is related to the growing body of work that explores the link between innovation and firm growth dynamics (Caballero and Jaffe, 1993; Klette and Kortum, 2004; Lentz and Mortensen, 2008; Acemoglu, Akcigit, Bloom, and William, 2011; Garcia-Macia et al., 2015) Existing approaches rely on calibration or estimation of structural models In contrast, our approach consists of building a direct measure of technological innovation implied by our model and using that measure to test the model’s predictions directly Our paper is also related to work that examines whether technological innovation leads to positive knowledge spillovers or business stealing Related to our paper is the work of Bloom, Schankerman, and Van Reenen (2013), who disentangle the externalities generated by R&D expenditures on firms competing in the product and technology space We contribute to this literature by proposing a measure of patent quality based on asset prices and assessing reallocation and growth dynamics after bursts of innovative activity Shea (1999) constructs direct measures of technology innovation using patents and R&D spending and finds a weak relationship between TFP and technology shocks Our contrasting results suggest that this weak link is likely the result of the implicit assumption in Shea (1999) that all patents are of equal value Indeed, Kortum and Lerner (1998) show that there is wide heterogeneity in the economic value of patents Furthermore, fluctuations in the number of patents granted are often the result of changes in patent regulation, or the quantity of resources available to the US patent office (see e.g Griliches, 1990; Hall and Ziedonis, 2001) As a result, a larger number of patents does not necessarily imply greater technological innovation Using R&D spending to measure innovation overcomes some of these issues, but doing so measures innovation indirectly The link between inputs and output may vary as the efficiency of the research sector varies over time or due to other economic forces (see e.g., Kortum, 1993) The measure proposed by Alexopoulos (2011) based on books published in the field of technology overcomes many of these shortcomings However, this measure is only available at the aggregate level, and may not directly capture the economic value of innovation to the firm In contrast, our measure is available at the firm level, which allows us to evaluate reallocation and growth dynamics across firms and sectors Electronic copy available at: https://ssrn.com/abstract=2193068 Finally, our paper is also related to productivity literature that has documented substantial dispersion in measured productivity across plants and firms (see e.g., Syverson, 2004) We contribute to this literature by constructing a direct measure of technological innovation and showing that it can account for a significant fraction of cross-firm dispersion in measured TFP in our sample Construction of the Innovation Measure Our main objective in this section is to obtain an empirical estimate of the economic value of the patent, defined as the present value of the monopoly rents associated with that patent To estimate this value, we combine information from patent data and firm stock price movements We proceed in two steps The first empirical challenge is to isolate the information about the value of the patent contained in stock prices from unrelated news To so, we focus on a narrow window following the date when the market learns that the patent application is successful The US Patent Office (USPTO) has consistently publicized successful patent applications throughout our sample Focusing on the days around this event allows us to isolate a discrete change in the information set of the market participants regarding a given patent However, even during a small window around the event, stock prices are likely to be contaminated with other sources of news unrelated to the value of the patent Therefore, our second step filters the stock price reaction to the patent issuance from the total stock return over the event window Next, we discuss the data used in constructing our measure and describe these two steps in more detail 1.1 Description of patent data We begin by first providing a brief description of the patent data; we relegate the details to the Online Appendix We download the entire history of U.S patent documents (7.8 million patents) from Google Patents using an automation script.4 First, we clean assignee names by comparing each assignee name to the more common names, and if a given name is close, according to the Levenshtein distance, to a much more common name, we substitute the common name for the uncommon name Having an assignee name for each patent, we match all patents in the Google data to corporations whose returns are in the CRSP database Some of these patents appear in the NBER data set and therefore are already matched to CRSP firms Remaining assignee names are matched to CRSP firm names using a name Google also makes available for downloading bulk patent data files from the USPTO The bulk data does not have all of the additional “meta” information including classification codes and citation information that Google includes in the individual patent files Moreover, the quality of the text generated from Optical Character Recognition (OCR) procedures implemented by Google is better in the individual files than in the bulk files provided by the USPTO This is crucial for identifying patent assignees Electronic copy available at: https://ssrn.com/abstract=2193068 matching algorithm Visual inspection of the matched names confirms very few mistakes in the matching We extract patent citations from the Google data and complement them with the hand-collected reference data of Nicholas (2008).5 Out of the 6.2 million patents granted in or after 1926, we find the presence of an assignee in 4,374,524 patents After matching the names of the assignees to public firms in CRSP, we obtain a database of 1,928,123 matched patents Out of these patents, 523,301 (27%) are not included in the NBER data Overall, our data provides a matched permco for 44.1% of all patents with an assignee and 31% of all granted patents By comparison, the NBER patent project provides a match for 32% of all patents from 1976–2006, so our matching technique is comparable, even though we use only data extracted from OCR documents for the period before the NBER data Last, another point of comparison is Nicholas (2008), who uses hand-collected patent data covering 1910 to 1939 From 1926–1929, he matches 9,707 patents, while our database includes 8,858 patents; from 1930–1939 he has 32,778 patents while our database includes 47,036 matches during this period After restricting the sample of patents to those with a unique assignee, those issued while the firm has non-missing market capitalization in CRSP, and for which we can compute return volatilities, we obtain a final sample of 1,801,879 patents 1.2 Identifying information events The first step in constructing our measure is to isolate the release of information to the market The US Patent and Trademark Office (USPTO) issues patents on Tuesdays, unless there is a federal holiday The USPTO’s publication, Official Gazette, also published every Tuesday, lists patents that are issued that day along with the details of the patent Identifying additional information events prior to the patent issue day is difficult, since before 2000, patent application filings were not officially publicized (see, e.g., Austin, 1993) However, anecdotal evidence suggests that the market often had advance knowledge of which patent applications were filed, since firms often choose to publicize new products and the associated patent applications themselves For now, we assume that the market value of the patent, denoted by ξ, is perfectly observable to market participants before the patent is granted We show how relaxing this assumption affects our measure in Section 1.4 below For the Google data, we extract patent citations from two sources First, all citations for patents granted between 1976 and 2011 are contained in text files available for bulk downloading from Google These citations are simple to extract and likely to be free of errors, as they are official USPTO data Second, for patents granted before 1976, we extract citations from the OCR text generated from the patent files We search the text of each patent for any 6- or 7-digit numbers, which could be patent numbers We then check if these potential patent numbers are followed closely by the corresponding grant date for that patent; if the correct date appears, then we can be certain that we have identified a patent citation Since we require the date to appear near any potential patent number, it is unlikely that we would incorrectly record a patent citation – it is far more likely that we would fail to record a citation than record one that isn’t there Electronic copy available at: https://ssrn.com/abstract=2193068 On the patent issue date, the market learns that the patent application has been successful Absent any other news, the firm’s stock market reaction ∆V on the day the patent j is granted would be given by ∆Vj = (1 − πj ) ξj , (1) where, πj is the market’s ex-ante probability assessment that the patent application is successful and ξj is the dollar value of patent j The market’s reaction to the patent grant (1) understates the total impact of the patent on the firm value, since the information about the probability that a patent will be granted is known to the market before the uncertainty about patent application is resolved.6 Next, we need to choose the length of the announcement window around the patent issuance event To guide our decision, we examine the pattern of trading volume on the stocks of firms that have been issued a patent We focus on the ratio of daily volume to shares outstanding We compute the ‘abnormal’ share turnover around patent issuance days, after adjusting for firm-year and calendar day effects As we see in Figure 1, there is a moderate and statistically significant increase in share turnover around the day that the firm is granted a patent – with most of the increase taking place on the first two days following the announcement.7 In particular, we find that the total abnormal turnover in the first two days after the announcement increases by 0.2% This is a significant increase when compared to the median daily turnover rate of 1.3% Even though prices can adjust to new information absent any trading, the fact that stock turnover increases following a patent grant is consistent with the view that patent issuance conveys important information to the market In sum, we conclude that two days after the patent issuance seems a reasonable window over which information about successful patent grant is reflected in the stock market We thus choose a three-day announcement window, [t, t + 2], for the remainder of our analysis when constructing our measure As robustness, we also extend the window to five days and obtain quantitatively similar results In addition to the patent issuance date, we examined stock price responses around other event dates, specifically, application filing and publication dates We find no significant stock price movements around application filing dates, consistent with the fact that the USPTO does not publish applications at the time they are filed After 2000, the USPTO started publishing applications eighteen months after the filing date We find some weak stock price movements around application publication dates Since publication-day announcements only occur in the post-2000 period, we not include the information from these dates since we did not want the statistical properties of the measures to be different across periods Our estimates imply that trading volume is temporarily lower prior to the patent issuance announcement A potential explanation is the presence of increased information asymmetry, with investors worrying about trading against potentially informed insiders who might know more about an impending patent issuance Similar patterns in trading volume have been documented before earnings announcements, see e.g., Lamont and Frazzini (2007) Electronic copy available at: https://ssrn.com/abstract=2193068 1.3 Some Illustrative Examples Before turning to our main analysis, we first examine some illustrative case studies to study the relation between the stock market reaction and important patent grants For these examples we performed an extensive search of online and print news sources to confirm that no other news events are likely to account for the return around the patent dates The first example is patent 4,946,778, titled “Single Polypeptide Chain Binding Molecules”, which was granted to Genex Corporation on August 7, 1990 The firm’s stock price increased by 67 percent (in excess of market returns) in the three days following the patent announcement Investors clearly believed the patent was valuable, and news of the patent was reported in the media For example, on August Business Wire quoted the biotechnology head of a Washington-based patent law firm as saying “The claims issued to Genex will dominate the whole industry Companies wishing to make, use or sell genetically engineered SCA proteins will have to negotiate with Genex for the rights to so.” The patent has subsequently proved to be important on other dimensions as well The research that developed the patent, Bird, Hardman, Jacobson, Johnson, Kaufman, Lee, Lee, Pope, Riordan, and Whitlow (1988), was published in Science and has since been cited over 1300 times in Google Scholar, while the patent itself has been subsequently cited by 775 patents Genex was acquired in 1991 by another biotechnology firm, Enzon News reports at the time indicate that the acquisition was made in particular to give Enzon access to Genex’s protein technology Another example from the biotechnology industry is patent 5,585,089, granted to Protein Design Labs on December 17, 1996 The stock rose by 22 percent in the next two days on especially high trading volume On December 20, the New York Times reported that the patent “could affect as much as a fourth of all biotechnology drugs currently in clinical trials.” As another illustration, consider the case of patent 6,317,722 granted to Amazon.com on November 13, 2001 for the “use of electronic shopping carts to generate personal recommendations” When Amazon filed this patent in September 1998, online commerce was in its infancy Amazon alone has grown from a market capitalization of approximately $6 billion to over $100 billion today The importance of a patent that staked out a claim on a key part of encouraging consumers to buy more – the now-pervasive “customers also bought” suggestions– was not missed by investors: the stock appreciated by 34 percent in the two days after the announcement, adding $900 million in market capitalization Our methodology is potentially helpful in distinguishing between innovations that are scientifically important and those that have a large impact on firm profits For example, consider patent 6,329,919 granted to IBM in 2001 for a “system and method for providing reservations for restroom use.” This patent describes a system to allow passengers on an airplane to reserve a spot in the bathroom queue The patent has subsequently been of such little value to IBM that the firm has stopped paying the annual renewal fee to the USPTO, and the patent has now lapsed Our method would identify this patent as having Electronic copy available at: https://ssrn.com/abstract=2193068 little economic value – the return over the 3-day window is slightly negative, and there is no change in the trading volume By contrast, citation counts indicate that this patent presented a considerable scientific advance – the patent has received 21 citations, which places it in the top 20% of the patents granted in the same year 1.4 Estimating the Value of a Patent The second step in constructing our measure is to isolate the component of firm return around patent issuance events that is related to the value of the patent In particular, the stock price of innovating firms may fluctuate during the announcement window around patent issuance for reasons unrelated to innovation Hence, it is important to account for measurement error in stock returns To remove market movements, we focus on the firm’s idiosyncratic return defined as the firm’s return minus the return on the market portfolio.8 We decompose the idiosyncratic stock return R for a given firm around the time that its patent j is issued as Rj = vj + εj , (2) where vj denotes the value of patent j – as a fraction of the firm’s market capitalization – and εj denotes the component of the firm’s stock return that is unrelated to the patent We construct our estimate ξ of the economic value of patent j as the product of the estimate of the stock return due to the value of the patent times the market capitalization M of the firm that is issued patent j on the day prior to the announcement of the patent issuance: ξj = (1 − π ¯ )−1 E[vj |rj ] Mj Nj (3) If multiple patents Nj are issued to the same firm on the same day as patent j, we assign each patent a fraction 1/Nj of the total value Since the unconditional probability π ¯ of a successful patent application is approximately 56% in the 1991-2001 period (see, e.g Carley, Hegde, and Marco, 2014), we account for this understatement by multiplying our estimates of patent values by 1/0.44 = 2.27.9 By using this ‘market-adjusted-return model’ (Campbell, Lo, and MacKinlay, 1997), we avoid the need to estimate the firm’s stock market beta, therefore removing one source of measurement error As a robustness check, we construct the idiosyncratic return as the firm’s stock return minus the return on the beta-matched portfolio (CRSP: bxret) This has the advantage that it relaxes the assumption that all firms have the same amount of systematic risk, but is only available for a smaller sample of firms Our results are quantitatively similar when using this alternative definition In principle, the ex-ante probability of a successful patent grant πj could vary with the private value of a patent ξ This possibility will induce measurement error in the estimated patent values Aggregating patent values within a firm (or year) will partly ameliorate this concern, as long as the joint distribution of π and ξ is stable within firm-years However, this need not be the case Carley et al (2014) use proprietary data Electronic copy available at: https://ssrn.com/abstract=2193068 Table A.3: Innovation and Firm Size Size (book assets) Patents, citation-weighted (Θcw ) 1.2 2.3 3.9 8.2 90.4 Citations to Patents 2.6 2.6 2.5 2.3 2.2 Patents, citation-weighted, scaled by assets (%) 6.6 4.4 3.0 2.5 2.4 Patents, citation-weighted, scaled by mkcap (%) 7.9 6.5 5.8 5.4 22.5 Patents, SM weighted (Θsm ) 0.3 1.2 3.5 15.5 603.8 Total Value to Number of Patents 0.6 1.1 2.0 4.3 18.1 Patents, SM weighted, scaled by assets (%) 3.5 3.3 3.5 4.7 10.6 Patents, SM weighted, scaled by mkcap (%) 1.8 2.4 2.8 3.9 12.3 Patents, citation-weighted (Θcw ) 1.3 3.4 6.0 14.9 81.4 Citations to Patents 2.2 2.4 2.5 2.5 2.3 Patents, citation-weighted, scaled by assets (%) 4.0 4.4 4.0 3.4 3.1 Patents, citation-weighted, scaled by mkcap (%) 21.9 9.8 7.2 6.0 3.4 Patents, SM weighted (Θsm ) 0.1 0.8 2.2 9.3 618.4 Total Value to Number of Patents 0.3 0.6 1.2 2.7 19.1 Patents, SM weighted, scaled by assets (%) 1.2 2.4 3.5 4.7 13.9 Patents, SM weighted, scaled by mkcap (%) 2.4 2.9 3.1 4.3 10.6 Size (Market cap of equity) Table reports mean value within each quintile SM values are deflated by CPI (units are USDm in 1982) Quintiles ¯j where Cj is are computed using annual breakpoints Citation-weighted patent counts are computed as j + Cj /C ¯ number of cites to patent j and Cj is the mean number of cites to patents granted in the same year as patent j 19 Electronic copy available at: https://ssrn.com/abstract=2193068 Table A.4: Firm-level innovation measure: changes in distribution across decades Decade Mean Sd p25 p50 p75 p90 p95 p99 1950 3.1 6.3 0.0 0.4 3.1 9.4 16.2 32.7 1960 4.7 10.0 0.0 0.0 4.7 14.4 23.8 51.6 1970 1.7 5.3 0.0 0.0 0.7 4.3 9.3 30.4 1980 1.2 4.0 0.0 0.0 0.0 3.1 8.1 21.7 1990 3.0 11.1 0.0 0.0 0.0 6.7 17.9 56.0 2000 5.6 19.2 0.0 0.0 1.5 14.6 32.6 86.5 Table reports the distribution of our baseline measure θfsm across decades Units are in percentage terms 20 Electronic copy available at: https://ssrn.com/abstract=2193068 Table A.5: Mean innovation across industries Ind Code Industry Name 10 11 12 13 14 15 16 17 18 19 21 22 23 24 25 26 27 28 Food Products Beer & Liquor Tobacco Products Recreation Printing and Publishing Consumer Goods Apparel Healthcare, Medical Equipment, Pharmaceutical Products Chemicals Textiles Construction and Construction Materials Steel Works Etc Fabricated Products and Machinery Electrical Equipment Automobiles and Trucks Aircraft, ships, and railroad equipment Precious Metals, Non-Metallic, and Industrial Metal Mining Coal Petroleum and Natural Gas Communication Personal and Business Services Business Equipment Business Supplies and Shipping Containers Transportation Wholesale Retail Restaurants, Hotels, Motels θcw θsm 0.76 0.16 0.32 2.19 0.66 4.02 0.51 9.09 6.97 1.05 2.50 1.78 6.67 8.09 4.67 6.22 0.52 0.23 0.72 0.41 2.15 7.45 2.78 0.05 0.42 0.13 0.05 0.98 2.10 1.59 1.39 0.18 3.48 0.22 9.13 5.93 0.33 1.20 1.38 3.66 4.58 2.72 3.85 0.32 0.09 1.43 0.67 2.25 7.19 2.39 0.05 0.24 0.12 0.03 Table reports mean value of normalized firm-level innovation θ (multiplied by 100) within each Fama-French industry (using their 30 industry classification) We exclude financial firms and utilities 21 Electronic copy available at: https://ssrn.com/abstract=2193068 Table A.6: Estimates of Patent Value: Descriptive Statistics Moment Mean Std Dev C C/C¯ Rf Baseline Exponential Cauchy E[v|Rf ] ξ E[v|Rf ] ξ E[v|Rf ] ξ (%) (%) USDm (%) USDm (%) USDm 10.26 20.13 1.18 1.98 0.07 3.92 0.32 0.20 10.36 32.04 0.40 0.30 12.79 39.75 0.15 0.11 5.13 16.13 0 11 24 38 90 0.00 0.00 0.00 0.20 0.62 1.38 2.78 4.06 8.84 -9.93 -5.15 -3.55 -1.67 -0.09 1.62 3.82 5.73 11.49 0.11 0.14 0.16 0.20 0.27 0.37 0.53 0.68 1.07 0.01 0.04 0.11 0.73 3.22 9.09 22.09 38.20 121.39 0.13 0.16 0.19 0.24 0.33 0.46 0.66 0.85 1.35 0.01 0.05 0.13 0.89 3.95 11.23 27.28 47.27 150.46 0.05 0.06 0.07 0.09 0.13 0.18 0.27 0.34 0.55 0.00 0.02 0.05 0.33 1.52 4.45 10.95 19.13 60.04 Percentiles p1 p5 p10 p25 p50 p75 p90 p95 p99 The table reports the distribution of the following variables across the patents in our sample: the number of future citations till the end of our sample period C; the number of citations scaled by the mean number of cites to patents ¯ the market-adjusted firm returns Rf on the 3-day window around patent grant dates; issued in the same year C; the filtered component of returns E[v|Rf ] related to the value of innovation – using equation (4); and the filtered dollar value of innovation ξ using equation (3) deflated to 1982 (million) dollars using the CPI In addition to the baseline case, we also report results using two alternative distributional assumptions First, we assume that the component of firm return due to the patent, v, is exponentially distributed with scale parameter 1/σv As before, we assume the signal-to-noise ratio is constant across firms; using our estimates from equation (6) in the paper, we obtain σv /σε ≈ 0.014, so we use that As before, we allow σε to vary by firm-year and follow the same exact procedure as in the baseline case Second, we assume that v is distributed according to a Cauchy truncated at zero with scale γv , while ε is distributed according to a Cauchy with parameter γε We estimate the scale of the noise term, γε , using one-half the interquartile range of firm-year idiosyncratic returns, with an adjustment similar to the equation in footnote 13 in the paper Regarding the estimation of the noise-to-signal ratio δ = γv /(γv + γε ), we can no longer estimate it using equation (6) in the paper because the variance of the Cauchy distribution does not exist Absent a different alternative, we use the same estimate as in the paper We restrict attention to the patents for which we have non-missing data on three day announcement return, market capitalization and return volatilities needed to compute ˆ measure The sample contains 1,801,879 patents our Θ 22 Electronic copy available at: https://ssrn.com/abstract=2193068 Table A.7: Forward Citations and Patent Market Values – Alternative Distributions (1) (2) (3) (4) (5) 0.013 (13.84) 0.004 (5.12) A Exponential log(1 + Cj ) 0.174 (9.99) 0.099 (9.44) 0.055 (10.28) B Cauchy log(1 + Cj ) 0.173 (10.25) 0.096 (9.49) 0.059 (10.35) 0.016 (12.86) 0.004 (4.84) TxC Y TxC Y Y TxC Y Y TxC F Y TxC FxT Controls Firm Market Capitalization Volatility Fixed Effects Table reports the equivalent of Table in the paper under two alternative distributional assumptions Panel A presents results under the assumption that the component of firm return due to the patent, V , is exponentially distributed with scale parameter 1/σv Panel B presents results under the assumption that v is distributed according to a Cauchy truncated at zero with scale γv , while ε is distributed according to a Cauchy with parameter γε See notes to Table A.6 for more details Table A.8: Innovation and Firm Profit Growth – Alternative Distributions A Exponential Firm Competitors 5 0.018 [3.61] 0.029 [4.49] 0.036 [3.74] 0.042 [3.81] 0.046 [3.60] -0.015 [-2.96] -0.029 [-5.05] -0.032 [-7.25] -0.035 [-5.98] -0.038 [-5.84] B Cauchy Firm Competitors 5 0.018 [5.74] 0.027 [5.95] 0.035 [5.18] 0.040 [4.98] 0.045 [4.97] -0.012 [-2.19] -0.024 [-3.40] -0.027 [-4.95] -0.031 [-5.05] -0.034 [-4.81] Table reports the equivalent of Table 4, Panel A in the paper under two alternative distributional assumptions Panel A presents results under the assumption that the component of firm return due to the patent, V , is exponentially distributed with scale parameter 1/σv Panel B presents results under the assumption that v is distributed according to a Cauchy truncated at zero with scale γv , while ε is distributed according to a Cauchy with parameter γε See notes to Table A.6 for more details 23 Electronic copy available at: https://ssrn.com/abstract=2193068 Table A.9: Innovation and Firm Growth: Results using Alternative Scaling (Market Capitalization) a Profits Firm Competitors 5 0.006 [2.45] 0.017 [5.53] 0.023 [4.34] 0.028 [4.21] 0.034 [4.07] -0.027 [-5.64] -0.034 [-3.29] -0.038 [-4.14] -0.043 [-4.33] -0.043 [-4.37] b Output Firm Competitors 5 -0.003 [-1.34] 0.001 [0.27] 0.003 [0.54] 0.012 [1.60] 0.021 [2.23] -0.041 [-6.23] -0.051 [-3.52] -0.058 [-3.65] -0.056 [-3.47] -0.064 [-3.84] c Capital Firm Competitors 5 0.003 [1.74] 0.007 [2.19] 0.011 [2.39] 0.015 [2.58] 0.021 [2.74] -0.013 [-3.33] -0.027 [-4.94] -0.039 [-5.63] -0.050 [-6.22] -0.062 [-6.71] d Labor Firm Competitors 5 -0.001 [-0.61] 0.002 [0.79] 0.006 [1.53] 0.011 [1.92] 0.014 [1.99] -0.019 [-6.19] -0.026 [-4.61] -0.032 [-5.29] -0.033 [-4.40] -0.032 [-4.23] e TFPR Firm Competitors 5 0.003 [1.09] 0.010 [3.17] 0.012 [2.74] 0.016 [4.22] 0.017 [4.74] -0.005 [-2.62] -0.009 [-3.59] -0.013 [-4.53] -0.013 [-3.09] -0.013 [-2.58] Table repeats the analysis in Table in the paper Rather than book assets, we now scale the firm’s dollar value of innovation by its end of year market capitalization Similarly, innovation by competing firms is constructed as the dollar value of innovation divided by their total market capitalization, in a manner analogous to equation (11) in the paper See notes to Table in the paper for more details 24 Electronic copy available at: https://ssrn.com/abstract=2193068 Table A.10: Innovation and Firm Profit Growth – Patent citations measured within a fixed window A Citations within 3-years of patent grant Firm Competitors 5 0.007 [4.41] 0.012 [4.92] 0.017 [5.08] 0.021 [4.99] 0.025 [5.31] -0.005 [-1.85] -0.006 [-1.56] -0.007 [-1.76] -0.006 [-1.13] -0.006 [-1.06] B Citations within 5-years of patent grant Firm Competitors 5 0.008 [4.73] 0.014 [5.58] 0.019 [5.35] 0.024 [5.35] 0.027 [5.71] -0.005 [-1.69] -0.007 [-1.78] -0.009 [-2.11] -0.007 [-1.43] -0.007 [-1.24] C Citations within 10-years of patent grant Firm Competitors 5 0.008 [4.86] 0.015 [5.77] 0.022 [5.62] 0.027 [5.69] 0.032 [6.59] -0.003 [-0.89] -0.005 [-1.29] -0.009 [-2.11] -0.007 [-1.28] -0.007 [-1.23] Table reports the equivalent of Table 5, Panel A in the paper under different ways of adjusting patent citations for truncation lags In each of the panels A, B, and C, we measure forward citations over the first N years after the patent is issued, where N = 3, 5, 10 We then repeat the analysis in Table by also excluding the last N years from the sample See notes to Table in the paper for more details 25 Electronic copy available at: https://ssrn.com/abstract=2193068 Table A.11: Innovation and Firm Growth: Controlling for R&D spending of Firm and Competitors Profits Firm a Competitors 5 0.017 [3.33] 0.027 [4.12] 0.034 [3.39] 0.039 [3.48] 0.043 [3.31] -0.018 [-3.24] -0.034 [-5.42] -0.037 [-8.23] -0.040 [-6.36] -0.045 [-6.38] b Output Firm Competitors 5 0.008 [2.85] 0.013 [3.07] 0.018 [2.85] 0.022 [2.62] 0.028 [3.15] -0.016 [-3.64] -0.034 [-6.33] -0.044 [-8.43] -0.048 [-7.91] -0.056 [-7.98] c Capital Firm Competitors 5 0.010 [8.40] 0.021 [6.69] 0.028 [5.76] 0.034 [4.40] 0.039 [4.13] 0.002 [0.38] -0.005 [-0.82] -0.012 [-1.59] -0.020 [-2.35] -0.029 [-3.15] d Labor Firm Competitors 5 0.007 [5.65] 0.014 [4.39] 0.019 [4.11] 0.023 [3.76] 0.025 [3.30] -0.007 [-1.64] -0.017 [-3.86] -0.021 [-4.34] -0.021 [-3.67] -0.019 [-3.00] e TFPR Firm Competitors 5 0.012 [2.18] 0.015 [2.07] 0.017 [2.56] 0.021 [3.28] 0.022 [3.98] -0.001 [-0.52] -0.006 [-2.20] -0.010 [-3.20] -0.015 [-4.59] -0.017 [-4.09] Table repeats the analysis of Table in the paper including the firm’s R&D spending as an additional control We control for the firm’s ratio of R&D spending to sales, as well as the ratio of total R&D spending to total sales of competing firms See notes to Table in the paper for additional details 26 Electronic copy available at: https://ssrn.com/abstract=2193068 Table A.12: Innovation and Firm Growth: Controlling for Measures of Investor Attention Horizon A Control for number of WSJ articles Firm Competitor N 0.017 [2.60] -0.033 [-13.84] 0.030 [4.31] -0.053 [-5.67] 0.036 [2.89] -0.047 [-5.53] 0.043 [3.23] -0.057 [-6.45] 0.045 [3.12] -0.074 [-6.78] 28966 26293 24077 19541 15529 B Control for number of analysts Firm Competitor N 0.011 [2.66] -0.020 [-2.47] 0.018 [4.45] -0.040 [-5.36] 0.022 [3.50] -0.042 [-7.12] 0.026 [3.37] -0.042 [-5.38] 0.028 [3.07] -0.046 [-4.99] 77483 69322 62209 55734 49858 control for institutional ownership Firm Competitor N 0.019 [3.18] -0.015 [-2.26] 0.029 [4.51] -0.032 [-4.33] 0.036 [3.70] -0.034 [-5.68] 0.040 [3.23] -0.037 [-4.53] 0.042 [3.00] -0.040 [-4.61] 70874 61737 53941 47165 41338 Table repeats the analysis in Table in the paper using additional controls for the degree of investor attention In panel A we control for the (log one plus the) number of articles that mention the firm in the Wall Street Journal The data is available over the 2000-2007 period The data is from matching news articles in Factiva to firms following the procedure in Butler and Gurun, 2012 In Panel B, we control for the (log of one plus the) number of analysts covering the stock The data is from I/B/E/S and covers the 1975-2010 period In Panel C, we control for the fraction of institutional ownership The data is from Thomson Reuters Institutional (13f) Holdings - Stock Ownership Summary and covers the 1980-2010 period See the notes to Table in the paper for additional details 27 Electronic copy available at: https://ssrn.com/abstract=2193068 Table A.13: Innovation and Firm Growth: IV using tax price of R&D Profits Firm a Competitors 5 0.116 [1.92] 0.221 [2.09] 0.273 [1.94] 0.352 [1.93] 0.409 [1.75] -0.116 [-2.54] -0.207 [-2.50] -0.266 [-2.37] -0.327 [-2.30] -0.373 [-2.08] b Output Firm Competitors 5 0.069 [1.91] 0.099 [1.60] 0.148 [1.67] 0.208 [1.76] 0.262 [1.69] -0.070 [-2.29] -0.134 [-2.49] -0.187 [-2.44] -0.233 [-2.35] -0.273 [-2.16] c Capital Firm Competitors 5 0.076 [2.12] 0.128 [2.02] 0.176 [2.00] 0.233 [2.04] 0.296 [1.97] -0.092 [-2.99] -0.171 [-3.06] -0.242 [-3.08] -0.319 [-3.12] -0.386 [-2.94] d Labor Firm Competitors 5 0.052 [1.64] 0.083 [1.43] 0.113 [1.39] 0.148 [1.39] 0.195 [1.39] -0.073 [-2.55] -0.139 [-2.76] -0.181 [-2.55] -0.213 [-2.28] -0.233 [-1.95] e TFPR Firm Competitors 5 0.092 [2.26] 0.149 [2.44] 0.170 [2.31] 0.212 [2.38] 0.229 [2.16] -0.063 [-1.81] -0.095 [-1.77] -0.117 [-1.78] -0.130 [-1.65] -0.142 [-1.55] Table repeats the analysis of Table in the paper using instrumental variables We use the R&D tax credit variation as an instrument for our innovation measure, following Bloom, Schankerman, and Van Reenen (2013) This R&D price is constructed at an annual level for each firm using state-level R&D tax credits See Bloom et al (2013) for more details on the construction of this variable We instrument for the firm’s own innovation θf t using the firm-level tax price; we instrument for the innovation by competing firms θI\f,t using the average R&D price of competing firms The first-stage F statistics vary from 17.1 to 61 across specifications and horizons We cluster standard errors by firm See notes to Table in the paper for additional details 28 Electronic copy available at: https://ssrn.com/abstract=2193068 Table A.14: Industry Output and Innovation – Comparison with Citation-Weighed Patents Horizon (years) A Industry output (quantity) SM 0.005 [2.73] 0.009 [2.49] 0.013 [2.83] 0.018 [3.02] 0.026 [3.29] 0.042 [3.49] 0.055 [3.32] 0.065 [3.23] R-sq 0.054 0.085 0.119 0.150 0.183 0.217 0.241 0.261 CW 0.007 [3.07] 0.016 [3.61] 0.024 [4.05] 0.031 [4.11] 0.038 [3.96] 0.044 [3.81] 0.049 [3.61] 0.053 [3.29] R-sq 0.051 0.086 0.119 0.148 0.176 0.197 0.215 0.229 B Industry output (value added) SM 0.001 [0.61] 0.002 [0.44] 0.004 [0.64] 0.007 [0.79] 0.012 [1.15] 0.027 [2.35] 0.038 [2.78] 0.047 [2.83] R-sq 0.014 0.027 0.044 0.059 0.077 0.098 0.121 0.140 CW 0.004 [1.57] 0.009 [1.75] 0.013 [1.77] 0.017 [1.76] 0.021 [1.78] 0.025 [1.75] 0.028 [1.68] 0.027 [1.45] R-sq 0.015 0.029 0.045 0.060 0.077 0.092 0.109 0.122 N 1395 1364 1333 1302 1271 1240 1209 1178 Table reports the relation between innovation and output growth at the industry level We construct industry-level innovation indices as i f ∈I Θf,t i , θI,t = f Bf t using both the market based measure (i = sm) as well as for cohort-adjusted, citation-weighted patent counts (i = cw) We report the estimated coefficients aτ from a specification similar to equation (12) in the paper, i xt+τ − xt = a0 + aτ θI,t + ρxt + ZIt + ut+τ where x is log industry output (quantity in Panel A, value added in Panel B) and Z is a vector of controls that includes log capital, log employment, mean industry id volatility and time effects We compute standard errors using i Newey-West To compare across the two measures, we scale θI,t to unit standard deviation 29 Electronic copy available at: https://ssrn.com/abstract=2193068 Table A.15: Innovation and Aggregate Growth – Comparison with Citation-Weighted Patents (1) (2) (3) (4) (5) (6) (7) (8) A Aggregate Output χcw 0.005 [1.08] 0.009 [1.10] 0.013 [1.36] 0.015 [1.40] 0.017 [1.70] 0.022 [2.31] 0.023 [2.24] 0.022 [2.13] R-sq 0.078 0.113 0.19 0.254 0.289 0.347 0.373 0.423 B Aggregate TFP χcw 0.004 [2.30] 0.007 [2.20] 0.011 [2.27] 0.016 [2.94] 0.02 [3.12] 0.022 [3.14] 0.023 [3.33] 0.026 [3.89] R-sq 0.201 0.305 0.397 0.493 0.535 0.559 0.592 0.652 Table repeats the analysis of Figure in the paper using an alternative index of innovation that is constructed using patent citations Specifically, in a direct analogy to equation (18) in the paper, the value of the index in year t is given by ˆ j∈Jt Cj χcw = , t Yt ˆ is the number of citations to patent j in the first 10 years since its grant date, Jt is the set of patents issued where C in year t (including both private and public firms) and Y is aggregate output Due to truncation, the sample ends in 2000 We report the estimated coefficients aτ from the following specification L xt+τ − xt = a0 + aτ log χ ˆcw + cl xt−l + ut+τ l=0 Here, x is log aggregate output (panel A) or log TFP (panel B) We scale log χ ˆcw to unit standard deviation We examine horizons of one to five years We select the number of lags L using the BIC criterion, which advocates a lag length of one to two years depending on the specification We compute standard errors using Newey-West 30 Electronic copy available at: https://ssrn.com/abstract=2193068 Filtered patent value, E[v|R] ·10−2 1.5 0.5 −0.2 −0.1 0.1 Firm stock return, R 0.2 0.3 Figure A.2: Plot compares the filtered values, E[v|R] across three different assumptions: our baseline case (black); the assumption that v is exponentially distributed (blue); the assumption that ε is Cauchy distributed and v follows a truncated Cauchy (at zero) See notes to Table A.7 for more details on the estimation of the parameters We use the sample mean for the variance (or scale) of the error term to draw these graphs We use the implied estimates from equation (6) in the main text to calibrate δ across the three cases 31 Electronic copy available at: https://ssrn.com/abstract=2193068 Figure A.3: Innovation and Aggregate Growth – VAR results (a) Output (b) TFP (i) scaled by GDP 04 01 02 005 −.02 Years 5 Years (ii) scaled by MKCAP 01 04 02 005 −.02 Years Years Figure shows impulse response of output per capita and productivity to innovation using bi-variate VARs We obtain impulse responses by ordering our innovation measure last We select lag length based on the BIC criterion Dotted lines represent 90% confidence intervals using standard errors are computed using 500 bootstrap simulations Productivity is utilization-adjusted TFP from Basu, Fernald, and Kimball (2006) Output is gross domestic product (NIPA Table 1.1.5) divided by the consumption price index (St Louis Fed, CPIAUCNS) Output per capita is computed using population from the U.S Census Bureau 32 Electronic copy available at: https://ssrn.com/abstract=2193068 References Basu, S., J G Fernald, and M S Kimball (2006) Are technology improvements contractionary? American Economic Review 96 (5), 1418–1448 Bloom, N., M Schankerman, and J Van Reenen (2013) Identifying technology spillovers and product market rivalry Econometrica 81 (4), 1347–1393 Hall, B., A J and M Trajtenberg (2001) The NBER patent citation data file: Lessons, insights and methodological tools Technical report, NBER Working Paper 8498 Nicholas, T (2008) Does innovation cause stock market runups? Evidence from the great crash American Economic Review 98 (4), 1370–96 Norvig, P (2009) Natural langugage corpus data In T Segaran and J Hammerbacher (Eds.), Beautiful Data O’Reilly Media 33 Electronic copy available at: https://ssrn.com/abstract=2193068 ... improvements in the technology frontier to resource reallocation and subsequent economic growth (Romer, 1990; Aghion and Howitt, 1992; Grossman and Helpman, 1991; Klette and Kortum, 2004) Since the value... end 3.2 Firm Innovation, Growth and Productivity We now examine the relation between innovation and firm growth and productivity Endogenous growth models imply that firm growth is related to innovation,... a strong relation between innovation, firm growth and the reallocation of resources across firms – For instance, Hall, Jaffe, and Trajtenberg (2005) and Nicholas (2008) document that firms owning